Effect of scutellarin on VEGF expression in human retinal pigment epithelial cells and retinas of diabetic rats

AIM: To evaluate the influence of scutellarin on the expression of vascular endothelial growth factor (VEGF) in high glucose-treated human retinal pigment epithelial cell line ARPE-19 and to observe the effects of scutellarin on the protein expression of VEGF, p-ERK and VEGFR2 in the retinas of type II diabetic rats. METHODS: Cultured ARPE-19 cells were divided into normal control group, scutellarin group, high glucose group and high glucose+scutellarin group. The protein levels of VEGF, p-ERK and VEGFR2 were measured by Western blot. The VEGF release in ARPE-19 cells was detected by ELISA. Normal rats were randomly divided into normal control group and scutellarin group. Diabetic rat model was established by feeding with high-fat diet and injecting with streptozocin, and randomly divided into diabetes group and diabetes treated with scutellarin group. After 16 weeks, the eyes were removed. The morphological changes of the retinas were observed under light microscope with HE staining, and histopathological score was recorded. The expression of VEGF in the retinas was observed by the method of immunohistochemistry. RESULTS: Compared with normal control group, the protein levels of VEGF, p-ERK and VEGFR2 in the ARPE-19 cells decreased in scutellarin group, but increased in high glucose group. The histopathological score of the retinas showed significant difference among diabetes group, diabetes treated with scutellarin group and normal control group, and no significant difference between normal control group and scutellarin group was observed. The expression of VEGF increased in diabetic group and was significantly higher than that in scutellarin treatment group (P<0.05). CONCLUSION: Scutellarin inhibits the increased protein le-vels of VEGF, p-ERK and VEGFR2 in ARPE-19 cells, and decreases the expression of VEGF in the retinas of diabetic rats. The suppression of the diabetic retinopathy development by scutellarin may be partly involved in the ERK/MAPK pathway.     

Relationship between 3-nitrotyrosine and myocardial cell apoptosis in rat diabetic cardiomyopathy

AIM: To explore the relationship between 3-nitrotyrosine (3-NT) level in hearts or blood and myocardial cell apoptosis in rat diabetic cardiomyopathy (DCM). METHODS: Sixty Sprague-Dawley (SD) rats (male, 8-week-old) were randomly divided into 4 groups: normal group, diabetic cardiomyopathy group (DCM group), diabetic rats treated with valsartan (40 mg·kg^-1·d^-1, D+V group) and DCM rats treated with valsartan (40 mg·kg^-1·d^-1, DCM+V group). Apoptotic index (AI) of rat cardiac myocytes was examined by TUNEL. The expression index (EI) of 3-NT in rat cardiac myocytes was examined by immunohistochemistry. The 3-NT concentration in rat serum was examined by ELISA. RESULTS: (1) Significant differences of the heart weight indexes among the 4 groups were observed (P<0.01). The heart weight indexes in DCM group and DCM+V group were higher than those in normal group and D+V group (P<0.01). (2) The EI of 3-NT in the cardiac myocytes was positively correlated with the AI of the cardiac myocytes in the same group (P<0.01), but the concentration of 3-NT in blood had no correlation with the AI of cardiac myocytes (P>0.05). (3) The difference of AI of cardiac myocytes among the 4 groups had statistical significance (P<0.01). The arrangement from high to low of AI was DCM group > D+V group and DCM+V group > N group (P<0.05). (4) The EI of 3-NT in DCM group was the highest as compared to other groups (P<0.05). (5) No statistical difference of 3-NT concentration in blood among the 4 groups was observed (P>0.05). CONCLUSION: (1) The expression of 3-NT in DCM myocardial tissues in SD rats is significantly increased and closely correlated with the apoptosis in myocardial cells. Valsartan inhibits 3-NT expression in DCM myocardial cells, thus inhibits the DCM myocardium apoptosis. (2) The 3-NT level in blood can not be true for reflection of 3-NT expression in DCM myocardial tissues and its effect on myocardial cell apoptosis.     

Effects of AT1 receptor autoantibody on renal cell apoptosis and JNK expression in diabetic nephropathy rats

AIM:To study the effects of angiotensin Ⅱ type 1 receptor autoantibody (AT1-AA) on the apoptosis of renal cell and the expression of c-Jun N-terminal kinase (JNK) in diabetic nephropathy (DN) rats. METHODS:High-sucrose and high-fat diet and intraperitoneal injection of streptozotocin were utilized to induce DN rat model. We employed enzyme-linked immunosorbent assay (ELISA) for serum AT1-AA and TUNEL staining for renal cell apoptosis. Furthermore, Western blotting was performed to measure the levels of endoplasmic reticulum stress (ERS) chaperone glucose-regulated protein 78 (GRP78) and ERS-associated apoptosis protein p-JNK. RESULTS:The renal cell apoptotic rate in DN group was significantly increased compared with NC group, and the apoptotic renal cells in AT1-AA positive DN rats were much greater than those in AT1-AA negative DN rats (P<0.05). The protein levels of GRP78 and p-JNK were significantly increased compared with NC group. GRP78 and p-JNK protein levels also significantly increased in AT1-AA positive DN rats compared with AT1-AA negative DN rats. CONCLUSION: AT1-AA activates ERS response and induces renal cell apoptosis via the JNK apoptotic pathway in the renal tissues of DN rats.     

Effects of insulin on VEGF expression in cultured retinal Müller cells

AIM: To investigate the effect of insulin on the expression of vascular endothelial growth factor(VEGF) in cultured rabbit retinal Müller cells. METHODS: Immunocytochemical method and ELISA were used to assay the change of VEGF expression in cultured Müller cells in vitro at different insulin concentrations in qualitative and quantitative ways. RESULTS: VEGF expression in retinal Müller cells was enhanced markedly by insulin. CONCLUSION: Insulin at high concentration enhances VEGF expression in cultured Müller cells, which may be one of factors that insulin accelerates the progress of diabetic retinopathy.     

Effects of fluctuant high blood glucose on apoptosis in glomerular endothelial cells and renal tubular epithelial cells in diabetic rats

AIM:To explore the effects of fluctuant high blood glucose and stable high blood glucose on apoptosis and the expression of Bax and Bcl-2 in glomerular endothelial cells and renal tubular epithelial cells in diabetic rats. METHODS: 24 SD rats were divided into 3 groups: control group, stable high blood glucose group and fluctuant high blood glucose group. Diabetic rats were induced by intraperitoneal injection of STZ, and the fluctuant high blood glucose animal model was induced by intraperitoneal injection of aspart and glucose at different time points every day. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL), and immunohistochemistry was used to detect apoptosis associated gene bax and bcl-2 expression in kidney. RESULTS:After 4 experimental weeks, a significant increase in cell apoptosis, up-regulation of Bax protein expression in kidney tubular epithelial cell and down-regulation of Bcl-2 in glomerular endothelial cell in fluctuant high blood glucose rats were observed compared with stable high blood glucose rats.CONCLUSION: Fluctuant high blood glucose induces more apoptosis in renal tubular epithelial cells than that in stable high blood glucose diabetic rats.     

Protective effects of sulforaphane on retinal neurons in diabetic rats

AIM: To clarify whether sulforaphane (SF) has protective effects on retina neuronal cells in diabetic rats and to identify the related mechanisms involved in this process. METHODS: The diabetic rat model was induced by single intraperitoneal injection of streptozotocin (STZ). The protective effects of SF were evaluated by measuring the generation of reactive oxygen species (ROS), detecting apoptosis of retina neuronal cells with TUNEL staining and counting the survival retinal ganglion cells (RGCs). The nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and the protein expression of heme oxygenase-1 (HO-1) were examined by immunofluorescence analysis and Western blot. RESULTS: SF treatment significantly attenuated ROS generation, decreased the apoptosis of retina neuronal cells and increased the numbers of survival RGCs in the diabetic rats. Meanwhile, SF significantly increased the nuclear accumulation of Nrf2 and the protein level of HO-1 in the retinas of diabetic rats. However, HO-1 inhibitor, protoporphyrin IX zinc (Ⅱ) diminished the inhibitory effects of SF on RGCs apoptosis. CONCLUSION: SF partially exerts the beneficial neuroprotective effects via the activation of the Nrf2/HO-1 antioxidant pathway, therefore alleviating retinal oxidative stress and decreasing the apoptosis of retina neuronal cells.     

Screening differentially expressed genes involved in apoptosis of primary cultured rat cerebellar granule neurons by mRNA differential display RT-PCR

AIM: To Screen and identify differentially expressed genes that involved in apoptosis model in rat cerebellar granule neurons (CGNs).METHODS: The rat cerebellar granule neurons were isolated and primarily cultured.Fluorescent differential display RT-PCR (FDD RT-PCR) was performed to screen differentially expressed ESTs in the apoptosis model of primarily cultured rat CGNs.ESTs were subcloned into pGEM-T EasyTM vector and then sequenced.Alignment assay in non-redunant database was applied for encoding information.Reverse Northern blotting was used to appraise the results from DDRT-PCR.RESULTS: 164 pieces of differentially expressed ESTs were obtained by FDDRT-PCR.17 of them were subcloned and sequenced.5 ESTs of 17 were confirmed to be positive results by reverse Northern blotting.CONCLUSION: DD-PCR is a rapid,simple-operation and sensitive method for screening differentially expressed genes,which would contribute to the molecular mechanisms of apoptosis/survive of CGNs.     

Cardiomyocyte apoptosis and related genes expression in sinoaortic-denervated rats

AIM: To study apoptosis and related genes expressions of cardiomyocytes in sinoaortic-denervated(SAD) rats. METHODS: SAD or sham-operation (Sham) was performed in male SD rats at the age of 10 weeks. After 16 weeks, apoptotic cells were stained in situ by terminal dexynucleotidyl-transferase mediated-dUTP nick end labeling (TUNEL). All stained results were analysised using computer image analysis techniques. Protein products and mRNA of Bcl-2, Bax, Fas and Fas-L were assessed by quantitative immunohistochemistry and RT-PCR. RESULTS: The numbers of apoptotic cardiomyocytes were significantly increased in SAD rats, the expressions of Bcl-2 were significantly decreased, whereas Bax,Fas and Fas-L were significantly increased in SAD rats.CONCLUSION: Apoptosis and dysregulation of gene expressions may be involved in the cardiomyocytes remodeling in SAD rats.     

Mechanism of vascular endothelial growth factor in diabetic rat retinopathy

AIM: To study the molecular mechanism of vascular endothelial growth factor (VEGF) in pathogenesis of diabetes in rats. METHODS: The diabetic rat model was established by using streptozocin. The animals were divided into normal control (C group), diabetic for one month (M₁ group), for three months (M₃ group) and for five months (M₅ group). In situ hybridization and immunohistochemistry were conduced to observe the expression of VEGF on retinal digest preparation and paraffin section. RESULTS: 1. On paraffin section: the positive rate of VEGF expression in M₅ group was 67% by in situ hybridization and 89% by immunohistochemistry. There was only 34% positive expression of VEGF in M₃ group by immunohistochemistry. 2. On retinal digest preparation: the VEGF positive expression rate in M₅ group was 34% by in situ hybridization and 56% by immunohistochemistry. CONCLUSION: Both endothelial cells and Mural cells and Müller cells express VEGF. The source of VEGF may be from the paracrine pathway in early stage of diabetic retinopathy.     

Protective mechanisms of ginkgolide B on rat retinal cell apoptosis induced by N-methyl-N-nitrosourea

AIM: To investigate the protective mechanisms of ginkgolide B (GB) on rat retinal degeneration induced by N-methyl-N-nitrosourea (MNU). METHODS: The rat retinal degeneration model was made. Photoreceptor cell apoptosis was measured by TUNEL assay. The expression of Bcl-2 and Bax in the different time points in the rat retina after treated with MNU was measured by RT-PCR and immunohistochemical methods. RESULTS: The outer nuclear layer cell apoptotic index in GB treatment group was significantly lower than that in model group (P<0.01). The bcl-2/bax mRNA ratios at scheduled time points of 12 h, 1 d, 2 d, 3 d and 5 d after MNU injection in model control were 0.36, 0.15, 0.29, 0.42 and 0.64, respectively, while the ratios in GB group were 0.98, 0.92, 0.53, 0.45 and 0.68, respectively, larger than those in model control group (P<0.01). No Bcl-2 positive expression was detected at any scheduled time points after MNU injection in model control group. Strong positive Bcl-2 expression was detected in GB group 1 d after MNU injection, decreased at the 2nd day and disappeared at the 3rd day. Compared with model control group, the Bax expression in GB group was significantly decreased (P<0.01).CONCLUSION: Ginkgolide B effectively inhibits the apoptosis of photoreceptor cells. The mechanism of GB action may be related to the increase in the expression of Bcl-2 and the increase in the ratio of Bcl-2/Bax.     

Expression and significance of stanniocalcin 2 in diabetic retinopathy

AIM To investigate the expression level of stanniocalcin 2 (STC2) in vitreous tissues of rats with diabetic retinopathy (DR), and to explore the relationship between STC2 and vascular endothelial growth factor (VEGF). METHODS Wistar rats were randomly divided into control group and DR group. The DR model was constructed by injection of streptozotocin. RT-qPCR, Western blot and ELISA were used to detect the expression levels of STC2 and VEGF in rat vitreous tissues. Rat retinal ganglion cells were treated with VEGFA, and the expression of STC2 was detected by RT-qPCR, Western blot and ELISA. The retinal ganglion cells were also treated with STC2 protein, and then the expression of VEGF was detected by RT-qPCR, Western blot and ELISA. Co-immunoprecipitation was used to detect the interaction between VEGF and STC2. RESULTS Compared with control group, the mRNA and protein levels of STC2 were significantly increased in vitreous tissues of the rats with DR, and the expression level of VEGF was also significantly increased in DR group (P<0.01). The expression level of STC2 was positively correlated with VEGF expression. VEGF induced the expression of STC2 in rat retinal ganglion cells and promoted its secretion. STC2 protein induced the expression and secretion of VEGF in rat retinal ganglion cells, and VEGF had certain interaction with STC2. CONCLUSION STC2 expression is significantly increased in vitreous tissues of the rats with DR, and is closely related to VEGF.     

Effects of piceatannol on rat kidney with diabetic nephropathy in early stage

AIM: To observe the effect of piceatannol on the kidney of diabetic nephropathy rats in early stage, and to explore the possible mechanisms.METHODS: The rats were randomly divided into 5 groups:control group, model group, low dose of piceatannol treatment group, medium dose of piceatannol treatment group and high dose of piceatannol treatment group. The rat model of diabetic nephropathy was induced accordingly, and the rats received 20 mg/kg, 40 mg/kg or 60 mg/kg of piceatannol by gavage once a day for 4 weeks. Blood glucose was detected by glucometer. The urea nitrogen and creatinine levels in the serum were measured by urease-glutamate dehydrogenase enzymatic and inosine acid oxidase methods, respectively, and 24 h urinary microalbumin was analyzed by immune transmission turbidimetry test. Moreover, the pathological changes of the kidney tissues were observed under microscope with HE staining. The protein expression of TGF-β1 and Smad 7 and the phosphorylation levels of Smad2 and Smad3 were determined by Western blot. RESULTS: Compared with model group, piceatannol treatment significantly decreased the levels of blood glucose, blood urea nitrogen and urinary microalbumin, but had no effects on serum creatinine. Furthermore, HE staining showed that the increased mesangial cells, matrix hyperplasia and degenerated epithelial cells in model group were markedly inhibited after piceatannol treatment. Additionally, piceatannol treatment also reduced the protein expression of TGF-β1 and Smad 7, and the phosphorylation levels of Smad2 and Smad3. CONCLUSION: Piceatannol attenuates pathological progression in the kidney of diabetic nephropathy rats in early stage, which may be through inhibiting TGF-β/Smad signaling pathway.     

Effect of Xuefuzhuyu decoction on cardiomyopathy in type 2 diabetic rats

AIM: To observe the pathologic changes of cardiomyopathy in type 2 diabetic rats and the therapeutic effect of Xuefuzhuyu decoction.METHODS: The diabetic model was established by feeding the animals with high-fat diet and injecting a middle dose of streptozotocin (50 mg/kg) intraperitoneally in 42 Wistar male rats. After 8 weeks, the damage of the heart in the model animals was detected by electrocardiogram and echocardiography, and the serum level of glucose, total cholesterol and triglyceride were determined by the methods of clinical chemistry. The content of collagen was quantified by Masson staining. The apoptosis of cardiomyocytes was measured by TUNEL apoptosis kit. The structures of myocardial damage were observed under light and electronic microscopes.RESULTS: (1) Compared with normal group at the same time points, the contents of serum glucose, triglyceride and cholesterol in model group increased (P<0.05). At the 11th and 14th weeks, the thickness of LVDS was significantly increased (P<0.01), the structure of myocardial tissues was severely damaged and collagen fiber content increased obviously (P<0.01). The cell apoptosis was also increased. (2) Compared with control group at the same time points, the contents of serum glucose, cholesterol and triglyceride in Xuefuzhuyu decoction group significantly decreased (P<0.05). The thickness of LVDS at the 11th and 14th weeks was decreased (P<0.05) and LVM at the 14th week became significantly thinner (P<0.01). The damage of the myocardium and subcellular structure was slighter and the content of collagen was lower than that in control group (P<0.05). The cell apoptosis was also attenuated.CONCLUSION: The levels of blood glucose, total cholesterol and triglyceride and the content of collagen fibers increase when diabetic cardiomyopathy develops, with more cell apoptosis and severe damage in the cardiac structure. Xuefuzhuyu decoction decreases the level of blood lipid in diabetic cardiomyopathy, alleviates the pathological changes of myocardial fibrosis and delays the progression of diabetic cardiomyopathy.     

Effects of Astragalus injection on neuronal apoptosis and expression of JNK3 in rat hippocampus after cerebral ischemia reperfusion

AIM:To investigate the effects of Astragalus injection on neuronal apoptosis and expression of c-Jun N-terminal kinase 3(JNK3) in the rat hippocampus after cerebral ischemia reperfusion. METHODS:The rat model of cerebral ischemia reperfusion was set up by a four-vessel occlusion method. The SD rats were randomly divided into 4 groups:sham operation group, cerebral ischemia reperfusion group(model group), cerebral ischemia reperfusion+Astragalus injection group(Astragalus injection group) and cerebral ischemia reperfusion+vehicle group(vehicle group). The rats in model group, Astragalus injection group and vehicle group after transient global cerebral ischemia(30 min) were then divided into 7 subgroups according to the reperfusion time of 0 h, 0.5 h, 2 h, 6 h, 24 h, 72 h and 120 h. The apoptosis of the neuron in the hippocampus was measured by the method of TUNEL staining. The expression of JNK3 at mRNA and protein levels was determined by real-time PCR and Western blotting,respectively. RESULTS:Compared with sham operation group, the number of apoptotic neurons increased in model group(P<0.05). Compared with model group, the number of apoptotic neurons decreased obviously in Astragalus injection group(P<0.05). Compared with sham operation group, the expression of JNK3 at mRNA and protein levels in the hippocampus increased obviously in model group at all time points except 120 h(P<0.05). Compared with model group, the expression of JNK3 at mRNA and protein levels in the hippocampus decreased obviously in Astragalus injection group at all time points except 120 h(P<0.05). CONCLUSION:Astragalus injection decreases neuronal apoptosis in rat hippocampus after cerebral ischemia reperfusion by inhibiting the expression of JNK3 at mRNA and protein levels.     

Effect of Ganoderma lucidum spores powder on the expression of IGF-1, NF-κB and apoptosis of nerve cells in the brain from epileptic rat

AIM: To investigate the effect of Ganoderma lucidum spores powder on the expression of insulin-like growth factor-1 (IGF-1), nuclear factor-κB (NF-κB) and apoptosis of nerve cells in rats with epilepsy established by pentetrazole. METHODS: The sub-eclampsia dosage of pentetrazole (PTZ) was used to make epilepsy model. Ganoderma lucidum spores powder group was given from stomach. The enduring time and latent period were recorded. The immune reactivity of IGF-1, NF-κB/P65 and apoptosis of nerve cells were measured with immunohistochemical staining and TUNEL method. RESULTS: In high power sight (×400), there were much more apoptosis cells in hippocampus and brain cortex of model group (18.80±2.13, 16.87±2.00) than those in control group (0.97±0.52, 0.58±0.25). The expressions of IGF-1, NF-κB in model group were higher than those in control group. Compared with model group, the latent period of Ganoderma lucidum spores powder group at the 17th, 21th, 25th days were longer (P<0.05, P<0.05, P<0.01, respectively).There were less apoptosis cells in hippocampus and brain cortex of Ganoderma lucidum spores powder group (12.30±2.46, 10.48±1.33) than those in model group. The expression of NF-κB/P65 in Ganoderma lucidum spores powder group was lower than that in model group, but the immune reactivity of IGF-1 increased more distinctly in Ganoderma lucidum spores powder group than that in model group. CONCLUSION: IGF-1, NF-κB and apoptosis of nerve cells may have play a role in occurrence and development of PTZ-induced epilepsy. Ganoderma lucidum spores powder can suppress expression of NF-κB strongly, and facilitate the immune reactivity of IGF-1, which may be one of the mechanisms by which Ganoderma lucidum spores powder restrains the apoptosis of nerve cells caused by epilepsy to prevent the damages of nerve cells.     

Effects of intermittent high glucose on apoptosis and PTEN expression in islet cells

AIM: To investigate whether the increase in PTEN expression is related to apoptosis, and whether it is regulated by reactive oxygen species(ROS). METHODS: The rat islet cells were divided into constant low glucose group (group L), constant high glucose group (group H), glucose fluctuation group (group F), low glucose after high glucose group (group HL) and low glucose after fluctuation group (group FL). The ROS level, apoptotic rate, intracellular calcium, insulin release and PTEN protein expression were analyzed. RESULTS: Compared with groups H and L, the insulin secretion decreased, and intracellular calcium, ROS level, PTEN protein expression and apoptotic rate increased in group F (P<0.05). Compared with group H, the intracellular calcium, ROS level, PTEN protein expression and apoptotic rate in group HL decreased, but were still higher than those in group L (P<0.05). Compared with group F, the intracellular calcium, ROS level, PTEN protein expression and apoptotic rate in group FL decreased, but were still higher than those in group L (P<0.05). CONCLUSION: Glucose fluctuation can cause the apoptosis of islet cells more easily than constant high glucose. This may be related to the change of intracellular calcium and increase in oxidative stress which promotes PTEN expression. The recovery of glucose level to some extent relieves oxidative stress, decrease PTEN expression and reduce cell damage.     

Effects of atorvastatin on iopromide-induced apoptosis of renal tubular epithelial cells in diabetic rats

AIM：To investigate the protective effect of atorvastatin (ATO) against contrast medium (CM)-induced apoptosis of renal tubular epithelial cells in diabetic rats. METHODS：Streptozocin-induced diabetic Wistar rats were fed for 8 weeks and then randomly divided into 5 groups: diabetes mellitus (DM) group, DM with iopromide (a kind of CM) treatment group (DM+CM group), and groups of DM rats treated with ATO at 5 mg·kg-1·d-1 (ATO1 group), 10 mg·kg-1·d-1 (ATO2 group) and 30 mg·kg-1·d-1 (ATO3 group) before iopromide injection. Healthy Wistar rats served as normal controls (N group). Urine creatinine (UCr) and 24-hour urinary albumin (24 h-UAlb) were determined 24 h after iopromide injection. Serum creatinine (SCr) and blood urea nitrogen (BUN) were detected 48 h after iopromide injection, and then creatinine clearance (CCr) and 24-hour urinary albumin excretion rate (24 h-UAER) were calculated. The rats were sacrificed and both kidneys were removed 48 h after iopromide injection. For the left kidney, the morphology by HE staining, the renal tubular apoptosis by TUNEL and the expression of Bax and Bcl-2 by immunohistochemistry were detected. For the right kidney, the expression of Bax and Bcl-2 was measured by Western blotting. RESULTS：Compared with N and DM groups, the levels of SCr, BUN and 24 h-UAER, as well as the expression of Bax in the renal medulla were higher, the levels of Ccr and Bcl-2 expression in the renal medulla were lower and TUNEL-positive cells were more in DM+CM group. Compared with DM+CM group, ATO attenuated these changes, especially in ATO3 group. CONCLUSION: Iopromide could cause renal tubular apoptosis. Early application of ATO could dose-dependently attenuate the development of contrast-induced acute kidney injury, partly due to suppression of iopromide-induced renal tubular apoptosis.     

Effects of norepinephrine preconditioning and ischemic preconditioning on apoptosis and Bcl-2, Bax expression in rat myocardial cells during myocardial ischemic reperfusion

AIM: To study the effects of norepinephrine preconditioning(NE-P) and ischemic preconditioning (IP)on apoptosis and Bcl-2, Bax expression in rat myocardial cells in myocardial ischemic reperfusion (I/R). METHODS: The model of rat ischemic-reperfusion was used to conduct NE-preconditioning. Apoptotic myocytes were detected with TUNEL. Bcl-2, Bax expression were detected with immunohistochemistry. RESULTS: The rate of apoptosis cells in I/R group was higher, the rate of apoptosis cells in NE-P group and IP was lower significantly than that in I/R group(P＜0.01). The expression of Bcl-2 in I/R group was lower, but the expression of Bax was higher, the expression of Bcl-2 in NE-P group was higher significantly than that in I/R group(P＜0.01), the expression of Bax in NE-P group was lower than that in I/R group(P＜0.01). There was no significantly difference between NE-P and IP group in the above parameters (P＞0.05). CONCLUSION: NE-P reduced myocyte apoptosis by I/R in rats; The expression of Bcl-2 ,Bax genes played an important role in myocardial apoptosis.     

Relationship between apoptosis,proliferation and expression,mutation of related genes in breast cancer

AIM:To study the relationship between apoptosis, proliferation and expression,mutation of related genes in breast cancer.METHODS:Methods of TUNEL, immunohistochemical S-P and PCR-SSCP were used respectively to study apoptotic index (AI), mitotic index(MI), expression of Bcl-2,p53,c-erbB-2,PCNA,Ki67,TopoⅡ and mutation of p53 in 54 cases of breast cancer.RESULTS:AI and MI were 9.40±3.78 and 5.96±2.36, respectively. There was a significant direct correlation between them(r=0.46.P＜0.01).High expression of Bcl-2,PCNA,Ki67,TopoⅡ coincided with high AI,MI(P＜0.01). High expression of p53,c-erbB-2 and mutation of p53 coincided with high MI(P＜0.01). Type of p53 mutation coincided with AI(P＜0.05).CONCLUSION:Disturbance of gene control between apoptosis and proliferation is related with expression,mutation of related genes in breast cancer.